POS1432 ROLE OF FAT AND MUSCLE TISSUE ON QUALITY OF LIFE OUTCOMES IN OSTEOARTHRITIS: RESULTS FROM THE KHOALA COHORT
Authors: A. C. Rat, J. Sellam, B. Mazières, W. Ngueyon Sime, P. Fardellone, F. Guillemin
Journal: Annals of the Rheumatic Diseases (2022)

Background The study of associations between body composition and osteoarthritis is still incomplete. While fat-related components are associated with pain in cross-sectional studies, longitudinal studies are rare and the impact on other quality of life (QOL) dimensions is not known. Objectives The main objective of the study was to analyze the impact of body composition on the evolution of the perceived health of patients followed for hip and knee osteoarthritis (OA). Methods Longitudinal data from the Knee and Hip Osteo Arthritis Long-term Assessment (KHOALA) cohort, a multicenter cohort of 878 patients with symptomatic knee and/or hip OA, were used. Body composition measures were obtained from DXA scans at year 3. Only 3 of the 6 investigating centers with Lunar Prodigy Advance DXA equipment recruited patients for this study. The main outcome criteria were the changes in Patient-Reported Outcomes Measures (PROms) (physical functioning, pain, mental health and vitality of the SF-36 0=worst,100=best) between 3 and 7 years of follow up. Body composition variables were as follows: fat mass index (FMI (kg/m 2 )), percentage of fat mass and trunk to leg fat mass ratio (TFM/LFM), skeletal muscle Mass Index (SMI (kg/m 2 )) and low lean mass if SMI &lt;7.00 kg/m 2 for men and &lt;5.5 kg/m 2 for women. To account for the correlation of repeated measurements of the same individual, generalized estimating equation (GEE) models were used to assess the associations between body composition measurements and the 4 SF-36 scores. The GEE models were adjusted for potential confusion covariates (age, sex, education level, occupation, smoking, comorbidity, hand OA, number of painful joints, joint of inclusion and Kellgren grade (KL)) showing a significant association at the 0.2 threshold in the bivariate analysis. Results 290 patients with knee and 114 patients with hip OA have been included in the analysis: women 254 (66.7%), mean age 60.3 (SD 8.4) years old, IMC 29.5 (5.7), KL grade2 135 (46.6%) for knee OA, 79 (69.3%) for hip OA. The results of the multivariate analysis of associations between anthropometric measures and quality of life dimensions are presented in Table 1. Table 1. Physical functionning Bodily pain Mental health Vitality β CI* 95% p β CI* 95% p β CI* 95% p β CI* 95% p FMI* -0.02 (-0.03;-0.01) &lt;.0001 -0.007 (-0.02;0.002) 0.14 0.0012 (-0.006;0.008) 0.76 -0.01 (-0.02;0.002) 0.02 TLF/LFM* 0.06 (-0.02;0.14) 0.12 0.03 (-0.06;0.12) 0.53 0.09 (0.02;0.15) 0.008 0.08 (0.002;0.17) 0.04 SMI* 0.01 (0.006;0.02) &lt;.0001 0.02 (0.01;0.02) &lt;.0001 Low LM -0.21 (-0.02;0.02) 0.02 Positive coefficients indicate that the outcome variable increased more for the observed group than for other participants. *The estimator expresses the variation of risk for an increase of 1 units of the variable. Analyses were adjusted on age, sex, education level, occupation, smoking, comorbidity, hand OA, number of painful joints Conclusion Increased FMI and the presence of low muscle mass (SMI) were associated with impaired functional ability, but not with pain, the associations of which disappeared after adjustment. Increased TFM/LFM and SMI were associated with improved mental health and vitality over time Disclosure of Interests Anne-Christine Rat Speakers bureau: Pfizer, Lilly, Abbvie, Galapagos, novartis, Consultant of: Pfizer, Lilly, Sanofi Genzyme, Abbvie, BMS, Jérémie SELLAM: None declared, Bernard Mazières: None declared, Willy Ngueyon Sime: None declared, PATRICE FARDELLONE: None declared, Francis Guillemin: None declared